Connecting the unconnected: NTNs and the rise of direct-to-device communications
By Paul Clowes, Business Development Director, Filtronic
Non-terrestrial networks (NTNs) and direct-to device (D2D) technologies offer the potential to overcome the digital divide by taking high-speed, low-latency data connectivity directly to remote and isolated parts of the world.
On a crowded planet a-buzz with constant data traffic, there remain large areas of the planet cut off from terrestrial communication networks. Successive generations of mobile communication technology have taken high-speed connectivity to the world’s most populated regions, and every-day life has come to depend on this ubiquitous connectivity. Yet the 5G goal of connecting every location on the planet remains elusive. In a world reliant on terrestrial mobile networks, a digital divide separates those with a broadband connection, whether fixed or mobile, from those without.
Out of reach: terrestrial network limitations
Earth-based communication networks can only reach so far. In remote or isolated regions, or in difficult terrain, the cost and physical challenges of installing telecommunications infrastructure are prohibitive. That leaves many people – especially in developing countries or rural communities – cut off from communication services, or with only low-speed connections.
Connectivity is important not just for improving communications and service access, but also for the multitude of applications that rely on internet-connected sensors and devices – from environmental and agricultural monitoring & control to automated industrial operations and smart home technologies. Connectivity is also critical in disaster-relief operations or conflict zones, where terrestrial networks may be destroyed.
What are NTNs and D2D technologies?
Non-terrestrial networks (NTNs) combined with direct-to-device (D2D) communications provide the most viable way to connect the unconnected. NTNs are wireless communication systems that operate above the Earth’s surface. They include satellites in low Earth orbit (LEO), medium Earth orbit (MEO) and geostationary orbit (GEO), as well as unmanned aerial vehicles (UAVs), such as high-altitude pseudo-satellites (HAPS) and drones.
In combination with NTNs, direct-to-device (D2D) technology can enable appliances – from smartphones to IoT devices – to communicate directly with satellites or UAVs, without additional hardware or reliance on terrestrial infrastructure.
NTNs already support backhaul connectivity for 5G and other wireless networks in areas where terrestrial infrastructure is inadequate. Filtronic technologies have been pivotal in enabling these high-volume data pipes to be developed in mmWave frequency bands for satellite networks, building on our expertise in terrestrial mobile communications.
Rising to the challenge
There are considerable challenges associated with developing NTN-enabled D2D-networks. With a finite RF spectrum, sufficient bandwidth must be allocated for data transmission in non-terrestrial channels. For the Feeder link satellite communications are moving into a higher mmWave bands such as Q, V &E as the more commonly used C, Ku and Ka bands become congested. Moving into these higher frequency bands brings significant technical challenges, but is an area Filtronic has a strong track record. These higher frequency bands are vital to delivering broadband connectivity for the underserved areas and achieving Ultra-Reliable Low Latency Communications (URLLC) required for real-time critical applications such as driverless vehicles.
Allocating radio frequencies and managing satellite orbit and access technologies is the responsibility of the International Telecommunication Union (ITU). It has been actively developing standards for NTNs through its 3GPP initiative, focusing on adapting 5G and other technologies for satellite connectivity. This will be essential to ensure that the benefits of using mmWave frequencies seen in terrestrial applications can be replicated for non-terrestrial networks.
NTN and D2D systems will need to be fully interoperable with terrestrial network equipment and infrastructure and will require careful frequency coordination with the mobile operators to prevent interference with existing terrestrial services. As the role of NTNs to deliver greater connectivity grows, so the ecosystem of devices and ground-based infrastructure will need to keep pace. That will involve developing compatible devices, encouraging operator adoption, establishing supply chains and evolving national regulations in line with new capabilities, to ensure the full potential of NTNs is realised.
Unlocking future possibilities
The most worthwhile immediate impact of developing NTN and D2D capabilities will be to bring vital connectivity to isolated communities and regions in crisis. Beyond this essential humanitarian goal, the connectivity delivered will bring significant speed and capacity improvements to enable exciting future possibilities.
NTNs, working in tandem with terrestrial networks, could enable major advances in operational efficiency, service quality and resilience for multiple industrial, commercial and public-safety applications and enterprises.
Delivering the promise of 6G will depend on ultra-reliable, high-frequency communications to achieve next-generation standards of speed, performance and capacity. All current visions for 6G involve using NTNs as a key enabler, opening the door to new applications such as remote surgery and augmented reality services.
NTNs could also turn up the dial on the Internet of Things, taking us into the realm of the Internet of Everything – where every object, system or entity on Earth can be monitored, tracked and optimised. All of these future possibilities rely on uninterrupted access to high-speed, high-volume data, every second of every day.
Building 5G connections via satellite
Filtronic is now supporting the European Space Agency and Viasat in a project to deploy non-terrestrial network LEO D2D systems across Europe and beyond, drawing on our expertise in high-power RF and mmWave technology.
The project partners are working to design and procure an open-architecture LEO network capable of delivering 5G non-terrestrial services directly to handheld devices. We are helping to define the optimal feeder link requirements for high-throughput uplink and downlink transmissions, and to develop the high-power RF solutions necessary for this new D2D network.
Look to the skies for next-generation connectivity
As demand for seamless, global broadband access grows, NTNs and D2D technologies – supported by advanced mmWave systems – will play a vital role in taking high-capacity, low-latency communications to every corner of the globe. If we are to breach the digital divide and bring data connectivity to those outside the reach of terrestrial networks, we must continue to look beyond the Earth and embrace the opportunities of networks in the sky.
Unlock the potential of the RF high-performance experts, talk to Filtronic today to see how we can advance your NTN and D2D projects.
For more information about Filtronic’s range of components and solutions, visit the website here. Alternatively, you can speak to a member of the team on +44 (0)1740 618 800.
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